Our eyes need food. They use nutrients to gain energy and maintain their complex structure and function. This is part of the homeostasis, or the balance of nature the human body requires to maintain its normal function. What happens if the eye is malnourished? What occurs in cases of malnutrition? Malnutrition is more frequent that it may first appear: obesity is the main issue, but intestine disorders are also common.
Obesity is a pandemic and according to the World Health Organisation (WHO), the global figure has tripled since 1975. And given its effects on health, treatment is sometimes aggressive. Increasingly more patients are receiving surgical treatment for obesity (bariatric surgery). This treatment has potential adverse effects due to malabsorption and reduced food intake which pose the risk of a micronutrient deficiency. Micronutrients are essential for the organism’s normal functioning. The most common deficiencies are: iron, folic acid and vitamin B12. The diets of these patients are often supplemented with iron and vitamins. However, the largely forgotten ones are the fat soluble vitamins: A, E, D and K. Their deficiencies are much less common, so we don't see them as often in the clinic.
Vitamin A (retinol) is essential for the photoreceptor in the retina to make the light-absorbing pigments. A vitamin A deficiency causes nyctalopia—night blindness—,the most common symptom. In fact, in Ancient Egypt it was discovered that the disorder improved through dietary management using liver (rich in vitamin A). A vitamin A deficiency also affects the eye’s surface. Retinol leads to cell differentiation, and may result in various disorders of the eye: conjunctival and corneal dryness, and keratomalacia.
A vitamin E deficiency (tocopherol), which functions as an anti-oxidant (it minimises “burnout” of the body’s metabolism), may cause neuromuscular disorders: ataxia, hyporeflexia, loss of sensitivity, ophthalmoparesis (ocular movement paralysis) and retinopathy.
Prevention is key for those patients in whom we induce temporary malabsorption to treat their obesity. With the supplements of these micronutrients, and timely eye check-up reminders, we can prevent, and where appropriate, diagnose and cure, disorders derived from poor nutrition.